Operating head for removing and fitting wheel tyres for vehicles

ABSTRACT

The operating head ( 1 ) for removing and fitting wheel tyres for vehicles, comprises a tool ( 8 ) for the fitting and/or removal of a tyre, associable with a tool-carrying arm ( 7 ) of a tyre-changing machine ( 2 ) and having an abutment portion ( 9 ) which can be positioned in correspondence of a stretch of the edge (B) of the rim (C) of a wheel (R) fixed on the tyre-changing machine ( 2 ), a force measuring device ( 11 ) linked together with the tool ( 8 ) and having a contact portion ( 12 ) arranged substantially in correspondence of the abutment portion ( 9 ) and able to be placed in contact with the edge (B) of the rim (C) to detect the force applied on the edge (B) along at least a direction of detection.

RELATED APPLICATION

This application claims the benefit of priority of Italian PatentApplication No. MO2014A000256 filed Sep. 12, 2014, the contents of whichare incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to an operating head for removing andfitting wheel tyres for vehicles.

It is well known that vehicle wheels generally comprise a metal rimhaving along its perimeter annular flanges among which the end portions,so-called “beads”, of an elastic tyre are inserted in adhering abutment.

The use is currently known of machines, so-called “tyre-changingmachines”, suitable for removing and fitting the tyre from/onto therelative rim to run, e.g., maintenance, repair or replacement jobs.

Different types of tyre-changing machines are known, in particular,comprising an operating head having a tool which can be shifted inheight and horizontally by the action of respective actuators and usablefor fitting and removing the tyre onto/from the rim.

The tools of known type generally have a lower abutment portion whichcan be positioned in correspondence of a stretch of the rim edge of awheel fixed on the machine, in order to allow the tyre removaloperations.

In addition, a particular type of known tools has a retractable nailwith a curved end part able to grip the tyre bead.

In particular, the nail is movable, due to the action of an actuatorcommonly mounted on the movable arm, between a bead fastening position,wherein it extends from the operating head to be interposed between theannular flange of the rim and a stretch of the tyre to be removed, andan extraction position of the tyre edge, wherein it is raised to extractthe stretch of the bead grasped above the rim annular flange.

During use, the operator adjusts the position of the operating head withrespect to the frame according to the specific dimensions of the wheel,and positions the tool resting on the rim edge.

The nail is then brought to the fastening position and the end partpresses the tyre flank as far as introducing itself between the tyrebead and the relative flange on the rim, so as to position the hookedextremity to retain the tyre bead. Subsequently, the nail is positionedin the extraction position so as to extract a portion of the bead abovethe rim.

The rotation of the rim then allows the coming out of the entyre beadfrom the respective flange.

The operating heads and tools of the known type generally have, however,some drawbacks.

In particular, the positioning of the lower portion of the tool on therim edge is carried out manually by the operator who, according tohis/her sensitivity, adjusts the force applied by the tool on the edgeof the rim itself.

This implies therefore the need to use qualified personnel and, in anycase, can result in damages to the rim during the positioning of thetool, or else subsequently, during the tyre removal job.

SUMMARY OF THE INVENTION

The main aim of the present invention is to provide an operating headfor removing and fitting wheel tyres for vehicles which allows toeliminate the risks of damaging the rim caused by an excessive pressureof the tool during the tyre fitting/removal operations.

Another object of the present invention is to provide an operating headfor removing and fitting wheel tyres for vehicles which allows toovercome the mentioned drawbacks of the prior art within the ambit of asimple, rational, easy, effective to use and affordable solution.

The above mentioned objects are achieved by this operating head forremoving and fitting wheel tyres for vehicles according to claim 1.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Other characteristics and advantages of the present invention willbecome better evident from the description of a preferred, but notexclusive embodiment of an operating head for removing and fitting wheeltyres for vehicles, illustrated by way of an indicative but non-limitingexample, in the accompanying drawings in which:

FIG. 1 is a view of the operating head according to the inventioninstalled on a tyre-changing machine;

FIG. 2 is an axonometric view of the operating head according to theinvention;

FIG. 3 is a side view illustrating the positioning of the operating headaccording to the invention in correspondence of a stretch of the rimedge of a wheel.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

With particular reference to such figures, reference number 1 globallyindicates an operating head installable on a tyre-changing machine 2 andusable for the fitting and/or removal of a tyre P onto/from the rim C ofa wheel R.

As illustrated by way of example in FIG. 1, the operating head 1 can beinstalled on a machine 2 for the removal and fitting of wheel tyres forvehicles of a conventional type.

For example, the machine 2 may comprise a bearing structure 3,substantially made up of a base 4 resting on the ground and of anupright 5 which rises from the base itself, locking means 6 of a rim Cof a wheel R supported by the base B and a tool-carrying arm 7 supportedmovable vertically and horizontally to the upright 5.

In particular, the operating head 1 can be fixed to the lower extremityof the tool-carrying arm 7 of the machine 2.

The operating head 1 comprising at least a fitting/removing tool 8associable with the tool-carrying arm 7 and having an abutment portion 9which can be positioned in correspondence of a stretch of the edge B ofthe rim C of the wheel R.

In particular, the tool 8 has attachment means 10, the type of one ormore threaded elements, able to allow the anchoring of the operatinghead 1 at the lower extremity of the tool-carrying arm 7.

Advantageously, the operating head 1 comprises a force measuring device11 linked together with the tool 8 and having a contact portion 12arranged substantially in correspondence of the abutment portion 9 andable to be placed in contact with the edge B of the rim C to detect theforce applied on the edge B along a respective direction of detection.

In particular, the force measuring device 11 comprises a force sensor13.

Preferably, the force sensor 13 is constituted by a load cell of thetype, e.g., of a shear load cell or the like.

Preferably, the force measuring device 11 also comprises at least afeeler element 14 having the contact portion 12 and associated with theforce sensor 13.

In particular, the feeler element 14 has a substantially elongatedconformation, extends along a direction of detection and has anextremity associated with the force sensor 13 and an opposite extremityhaving the contact portion 12.

With reference to the particular embodiment illustrated in the figures,the force sensor 13 is anchored to the body of tool 8 by means of atleast one holding bracket 15. A different fastening of the force sensor13 to the tool 8 cannot however be ruled out.

Different embodiments of the force measuring device 11 cannot also beruled out in which, e.g., the contact portion 12 is made up of a portionof the tool 8 and the force sensor 13 is integrated in the tool itself.

Advantageously, the operating head 1 may comprise a plurality of forcesensors 13 having respective contact portions 12 able to engage incorrespondence of respective portions of the edge B of the rim C, inorder to detect the forces applied on the edge B along differentdirections of detection.

Furthermore, the machine 2 has movement means for moving the operatinghead 1 along a vertical direction, not shown in the illustrations,operatively connected to the force sensor 13 and able to vary thepressure of the contact portion 12 of the operating head 1 on the edge Bof the rim C depending on the force detected by the force sensor 13.

Advantageously, said movement means are able to vary the position of theoperating head 1 also during the removal or fitting operations of thetyre, depending on the force variations detected by the force sensor 13.

In this way it is possible to avoid any damage to the rim due to, e.g.,variations in the inclination or the conformation of the surface of theedge B of the rim C. Still with reference to the particular embodimentillustrated in the figures, the operating head 1 comprises a movablenail 16 supported by the tool 8 and having a substantially hook-shapedfree extremity.

The movable nail 16 is able to be moved by the action of actuator means17 between a fastening position, wherein it extends from the tool 8beyond the abutment portion 9 to be inserted between the edge B of therim C and the tyre P and to position the free extremity below the beadof the tyre P, and an extraction position, wherein the free extremity isarranged in correspondence of the abutment portion 9 to extract the beadof the tyre P above the edge B of rim C.

It has in practice been ascertained how the described invention achievesthe proposed objects.

In particular the fact is underlined that the presence of the forcemeasuring device allows to eliminate the risks of damaging the rimcaused by an excessive pressure by the tool during the tyrefitting/removal operations.

What is claimed is:
 1. Operating head (1) for removing and fitting wheeltyres for vehicles, comprising at least a tool (8) for the fittingand/or removal of a tyre, associable with a tool-carrying arm (7) of atyre-changing machine (2) and having at least an abutment portion (9)which can be positioned in correspondence of a stretch of the edge (B)of the rim (C) of a wheel (R) fixed on said tyre-changing machine (2),and at least a force measuring device (11) linked together with saidtool (8) and having a contact portion (12) arranged substantially incorrespondence of said abutment portion (9) and able to be placed incontact with said edge (B) of the rim (C) to detect the force applied onsaid edge (B) along at least a direction of detection.
 2. Operating head(1) according to claim 1, wherein said force measuring device (11)comprises at least a force sensor (13).
 3. Operating head (1) accordingto claim 2, wherein said force sensor (13) comprises at least a loadcell (13).
 4. Operating head (1) according to claim 1, wherein saidforce measuring device (11) comprises at least a feeler element (14)having said contact portion (12) and associated with said force sensor(13).
 5. Operating head (1) according to claim 4, wherein said feelerelement (14) has a substantially elongated conformation, extendssubstantially along said direction of detection and has an extremityassociated with said force sensor (13) and an opposite extremity havingsaid contact portion (12).
 6. Operating head (1) according to claim 1,wherein said force measuring device (11) is anchored to said tool (8) bymeans of at least a holding bracket (15).
 7. Operating head (1)according to claim 1, wherein said contact portion (12) is made of atleast a portion of said tool (8).
 8. Operating head (1) according toclaim 1, comprising a plurality of said force measuring devices (11)having respective contact portions (12) able to be placed in contactwith respective portions of said edge (B) of the rim (C) to detect theforces applied on said edge (B) along different directions of detection.9. Operating head (1) according to claim 1, wherein said tool (8)comprises attachment means (10) associable with said tool-carrying arm(7) of the tyre-changing machine (2).
 10. Operating head (1) accordingto claim 1, comprising at least a movable nail (16) having asubstantially hook-shaped free extremity, associated with said tool (8)and movable between a fastening position, wherein said movable nail (16)extends beyond said abutment portion (9) to be inserted between saidedge (B) of the rim (C) and the tyre (P) of said wheel (R) and toposition said free extremity below the bead of said tyre (P), and anextraction position, wherein said free extremity is arranged incorrespondence of said abutment portion (9) to extract said bead of thetyre (P) above said edge (B) of the rim (C).
 11. Machine (2) forremoving and fitting wheel tyres for vehicles, comprising at least abearing structure (3), locking means (6) of a rim (C) of a wheel (R) forvehicles and at least a tool-carrying arm (7) associated movable withsaid bearing structure (3), wherein said tool-carrying arm (7) has atleast an operating head (1) according to claim
 1. 12. Machine (2)according to claim 11, comprising movement means for moving saidoperating head (1) operatively connected to said force measuring device(11) and able to vary the pressure of said contact portion (12) of theoperating head (1) on said edge (B) of the rim (C) depending on theforce detected by said force measuring device (11).